Fix Logger and other build issues (#7)

This branch fixes a couple of issues with the build
- stop linking everything in a library which is then linked against a single main. It doesn't work the way I wanted. If functionality needs to be exposed by a library, it can be done later or with a separate target
- This should also fix spdlog
- Source files are now in a separate meson file using mesons files() feautre
- Improve coverage generation by adding a script generating html coverage reports. This will hopefully keep the motivation higher to create more unit tests
- Increase the code coverage a bit to demonstrate that statement above is not a fluke 😄

Reviewed-on: #7

.gitignore

@@ -1,9 +1,13 @@
+# Folder
 builddir/
+ptouch-print/
 subprojects/*
-!subprojects/*.wrap
 .cache/
+coverageReport/
+
+# Files
+!subprojects/*.wrap
 .vscode/*
 !.vscode/c_cpp_properties.json
 !.vscode/settings.json
 !.vscode/launch.json
-ptouch-print/